Question

Which of the following gives a real image?

(Convex, plane, concave, none, all)

An object is placed in front of a convex mirror at a distance of 30 cm. The radius of the curvature of the mirror is 20 cm. The image formed is

(give length, position, larger/smaller)

Answer 1

E PAGE No. 1. (A) since it is not specified in the question, lachether it is asked for morror or lens, Home real image is obtained from concave mviror convex lens. and of the 30 cun C= 20 cm curature of (6 Given the distance object from the invirar u= the radius of currature of of the nviror kle know the focal length and the radius of the the mviror are related af 7 f = C = 20cm focal lengths of the conves mission = locm. We have the mirror formula relating the object distane image or distance and the focal length of the movear as =10 cm 2 ブ + 1 distance 1 f ha u= distance of object of image from mover fecom misviar

PAGE No. 2, ...... Since object is placed in front of the convex mviror Mes take uz + 30cm Focal length of convex mirror is taken as negative te - f 10 cm 4 1 tl u 1 + 1 - 1o 30 - . 10 - 1 30 =-3-1 -4 30 30 I 4 30 - 30 2 -7.5 cm o The image is formed at a distance of 7.5cm behind the convex miseran . The negative negative sign indicates that the is formed behind the mirror fic. the image formed virtual) image

30 lo la 20 f 2- to 13 The image formed is thus 1) virtual 2) erect 3 diminished 4) behind the winner at 7.5cm.